Fatty acid esters generally contain at least several milligrams per kilogram to several tens of milligrams per kilogram of sulfur components. Here, fatty acid esters mean esters of a fatty acid and glycerin (triglycerides, diglycerides and monoglycerides), esters of a fatty acid and a monohydric alcohol having 1 to 22 carbon atoms (fatty acid alcohol esters) and the like. When an alcohol is produced through hydrogenation of such a fatty acid ester in the presence of a catalyst for ester reduction, sulfur components contained in the fatty acid ester act as catalytic poisons of the reduction catalyst and reduce the catalytic activity markedly. Since the catalyst life becomes very short, it is necessary to replace the catalyst with a new one frequently, and the decrease in the operating ratio of the facility and the like are unavoidable.
As a method for removing sulfur components from a fatty acid ester, JP-A-2007-224272 discloses a method in which an adsorbent containing a metal such as Ni or Cu is used and a sulfur-containing compound is chemically hydrocracked in a hydrogen atmosphere and adsorbed to the adsorbent.
In the field of petrochemistry, desulfurization catalysts containing cobalt, molybdenum, nickel or the like as the main component are used. In order to improve the desulfurization activity for each of hydrogenation desulfurization of hydrocarbon oil in JP-A-2004-277597 and hydrogenation desulfurization of naphtha in JP-A-2009-523596, attempts have been made to regulate the mean pore diameter of the catalyst to be 6 to 15 nm or regulate the median pore size of the catalyst to fall within the range of 15 to 200 nm.
JP-A-2009-255047 discloses a honeycomb structure which is formed by integral molding of a honeycomb member used for treating exhaust gas from an internal-combustion engine and inorganic fibers. The pores of 0.005 to 0.03 μm in the honeycomb structure mainly contribute to the removal of chemically harmful substances, and the pores with a pore size of 1 to 50 μm reduce the pressure loss and increase the collection efficiency of PM (particulate matters).